As a GM who allows optimization of characters, I have a couple of players that have tendencies to min-max their sheets, and noticed that one in particular has no trouble at all getting a ranged attack or a defense to a cost of 1, allowing him to get 10HD for a measly 20 points... 40 points for 10HD in both offense and defense...

We're trying a new House Rule, HD have a maximum width of 2. This means that they're mostly just for automatic-success, and generally won't be bought at more than 2HD. Having multiple HD will work, in that losing an HD or 2 to penalties will still allow you to automatically succeed if you have 3+ or 4+ HD respectively, but less effective than just buying 1WD instead. Good for null powers, or powers that aren't resisted, and even for offensive/defensive powers, since gobbling even a couple of die is useful, and they still work in unison with WD and regular D.

I will say, Wild Talents is not really a system that lends itself to too much optimization, people need to be reasonable. Case in point, one of the rulebooks has a custom power to put out the sun, from earth, with no chance of failure. It's important to establish a character, then flesh out powers that make sense, if you just start with powers without an idea where you want them to end, it can get silly.

Well, I will do my best to optimize my house rules in a way that lends itself to as much optimization the players want to throw at it. That's kinda the idea of House Rules.

As for a custom power to put out the sun, the Range/Booster levels, and the Radius levels you'd have to reach in order to perform such a feat would make the power astronomically expensive... I'd surely allow it, but who would want to make it? o.O As we've discovered with Telekinesis... to have a really decent "super power", you end up with a base 16/32/64 per Quality, very quickly. The system is mostly sound, it just needs minor refinements, and a 2-width maximum on HDs seems a good start. There's still reason to buy up to 5HD (since HD's are the first to go when penalties apply, or multi-actions are attempted), but they're not as powerful anymore... No 10HD's on character sheets.

And usually, the powergamer types do establish a character first, then optimize the numbers to match that establishment as optimally as possible...